ELECTROWETTING DEVICE WITH POLYMER ELECTRODE

• US 20100177386A1
• Filed: 06/27/2008
• Published: 07/15/2010
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Invenios France SAS (Corning Incorporated)
• Original Assignee: Varioptic (Corning Incorporated)
• Inventors: Legrand, Julien, Boulin, Yves-Sebastien, Berge, Bruno, Maillard, Mathieu, Laune, Frederic
• Granted Patent: US 7,940,467 B2
• Time in Patent Office: Days
• US Class Current: 359/557
• CPC Class Codes: G02B 26/004 based on a displacement or a deformation of a fluid
• CPC Class Codes: G02B 3/14 of variable focal length

Abstract

The invention concerns an electrowetting optical device comprising a chamber (15) comprising first and second immiscible liquids (16, 18) contacting each other at a liquid-liquid interface (19), the first liquid being an insulating liquid and the second liquid being a conducting liquid; a first electrode (20) in the contact with the second liquid; and a second electrode (202) insulated from the first and second liquids by an insulating layer, wherein the second electrode is formed of a conductive molded polymer material, wherein the curvature of said liquid-liquid interface is controllable by application of a voltage between said first and second electrodes.

Claims

1. An electrowetting optical device comprising:

a chamber comprising a first immiscible liquid and a second immiscible liquid contacting each other at a liquid-liquid interface, wherein the first immiscible liquid is an insulating liquid and the second immiscible liquid is a conducting liquid;

a first electrode in contact with the second immiscible liquid; and

a second electrode insulated from the first immiscible liquid and the second immiscible liquid by an insulating layer, wherein the second electrode is formed of a conductive molded polymer material, wherein curvature of the liquid-liquid interface is controllable by application of a voltage between the first electrode and the second electrode, and wherein the conductive molded polymer material has a Water Vapour Transmission below 0.15 g.mm/m².day.

2. The electrowetting optical device of claim 1, wherein the second electrode is formed of a copolymer material comprising an intrinsically conductive polymer.

3. The electrowetting optical device of claim 1, wherein the conductive molded polymer material is made conductive by an introduction of conductive particles.

4. The electrowetting optical device of claim 3, wherein the conductive molded polymer material is a thermo plastic polymer.

5. The electrowetting optical device of claim 1, wherein the conductive molded polymer material is a thermosetting polymer.

6. The electrowetting optical device of claim 3, wherein the conductive molded polymer material comprises particles of carbon.

7. The electrowetting optical device of claim 6, wherein the conductive molded polymer material comprises carbon nanotubes.

8. The electrowetting optical device of claim 1, wherein the second electrode is injection molded.

9. The electrowetting optical device of claim 1, wherein the second electrode has a conductivity in the range of 10⁴ to 10⁷ Ohm.cm.

10. The electrowetting optical device of claim 1, wherein the second electrode comprises a plurality of contact points, wherein each of the plurality of contact points is configured to receive an independent voltage for controlling different parts of the liquid-liquid interface.

11. The electrowetting optical device of claim 1, wherein a body comprises the second electrode and a molded non-conductive polymer part.

12. The electrowetting optical device of claim 1, comprising a cap and a body separated by a gasket, wherein the second electrode forms at least a part of the body.

13. The electrowetting optical device of claim 1, arranged to provide, upon application of at least one independent voltage, at least one function selected from a group consisting of variable focus, variable tilt, and variable astigmatism.

14. The electrowetting optical device of claim 1, wherein the second electrode comprises a conical surface arranged to contact an edge of the liquid-liquid interface.

15. An optical apparatus comprising:

an image sensor for capturing an image;

a lens arrangement arranged to form the image on the image sensor, wherein the lens arrangement comprising an optical device, wherein the optical device comprises;

a chamber comprising a first immiscible liquid and a second immiscible liquid contacting each other at a liquid-liquid interface, wherein the first immiscible liquid is an insulating liquid and the second immiscible liquid is a conducting liquid;

a first electrode in contact with the second immiscible liquid; and

a second electrode insulated from the first immiscible liquid and the second immiscible liquid by an insulating layer, wherein the second electrode is formed of a conductive molded polymer material, wherein curvature of the liquid-liquid interface is controllable by application of a voltage between the first electrode and the second electrode, and wherein the conductive molded polymer material has a Water Vapour Transmission below 0.15 g.mm/m².day; and

driving circuitry configured to generate at least one voltage applied between the first electrode and the second electrode.

16. The optical apparatus of claim 15, further comprising:

a motion detector for detecting motion of the optical apparatus, wherein the optical device is arranged to shift the image formed on the image sensor in response to a motion detected by the motion detector.

17. The optical apparatus of claim 15, wherein the driving circuitry is configured to:

generate a first oscillating voltage of a first frequency, wherein the first frequency is applied between the first electrode and a first contact of the second electrode, and

generate a second oscillating voltage of a second frequency, wherein the second frequency is different than the first frequency, and wherein the second frequency is applied between the first electrode and a second contact of the second electrode.

18. A mobile telephone comprising an optical apparatus, the optical apparatus comprising:

an image sensor for capturing an image;

a lens arrangement arranged to form the image on the image sensor, wherein the lens arrangement comprising an optical device, wherein the optical device comprises;

a chamber comprising a first immiscible liquid and a second immiscible liquid contacting each other at a liquid-liquid interface, wherein the first immiscible liquid is an insulating liquid and the second immiscible liquid is a conducting liquid;

a first electrode in contact with the second immiscible liquid; and

a second electrode insulated from the first immiscible liquid and the second immiscible liquid by an insulating layer, wherein the second electrode is formed of a conductive molded polymer material, wherein curvature of the liquid-liquid interface is controllable by application of a voltage between the first electrode and the second electrode, and wherein the conductive molded polymer material has a Water Vapour Transmission below 0.15 g.mm/m².day; and

driving circuitry arranged to generate at least one voltage applied between the first electrode and the second electrode.

19. A digital camera comprising the optical apparatus, the optical apparatus comprising:

an image sensor for capturing an image;

a lens arrangement arranged to form the image on the image sensor, wherein the lens arrangement comprising an optical device, wherein the optical device comprises;

a chamber comprising a first immiscible liquid and a second immiscible liquid contacting each other at a liquid-liquid interface, wherein the first immiscible liquid is an insulating liquid and the second immiscible liquid is a conducting liquid;

a first electrode in contact with the second immiscible liquid; and

a second electrode insulated from the first immiscible liquid and the second immiscible liquid by an insulating layer, wherein the second electrode is formed of a conductive molded polymer material, wherein curvature of the liquid-liquid interface is controllable by application of a voltage between the first electrode and the second electrode, and wherein the conductive molded polymer material has a Water Vapour Transmission below 0.15 g.mm/m².day; and

driving circuitry arranged to generate at least one voltage applied between the first electrode and the second electrode.

20. A process for forming the electrowetting optical device comprising:

forming a second electrode by molding the polymer material using a mold, wherein the electrowetting optical device comprises;

a chamber comprising a first immiscible liquid and a second immiscible liquid contacting each other at a liquid-liquid interface, wherein the first immiscible liquid is an insulating liquid and the second immiscible liquid is a conducting liquid;

a first electrode in contact with the second immiscible liquid; and

a second electrode insulated from the first immiscible liquid and the second immiscible liquid by an insulating layer, wherein the second electrode is formed of a conductive molded polymer material, wherein curvature of the liquid-liquid interface is controllable by application of a voltage between the first electrode and the second electrode, and wherein the conductive molded polymer material has a Water Vapour Transmission below 0.15 g.mm/m².day.

21. The process of claim 20, wherein forming the second electrode by molding the conductive molded polymer material comprises injection molding the second electrode.